Re: [PATCH][ARM][3/3] Expand mod by power of 2

[Kyrill Tkachov <kyrylo.tkachov@arm.com>]

Ping.

Thanks,
Kyrill
On 19/08/15 13:50, Kyrill Tkachov wrote:
> Ping.
> https://gcc.gnu.org/ml/gcc-patches/2015-08/msg00448.html
>
> Thanks,
> Kyrill
>
>> -----Original Message-----
>> From: gcc-patches-owner@gcc.gnu.org [mailto:gcc-patches-
>> owner@gcc.gnu.org] On Behalf Of Kyrill Tkachov
>> Sent: 10 August 2015 12:14
>> To: GCC Patches
>> Cc: Ramana Radhakrishnan; Richard Earnshaw; Marcus Shawcroft; James
>> Greenhalgh
>> Subject: Re: [PATCH][ARM][3/3] Expand mod by power of 2
>>
>> Here is a slight respin.
>> The important parts are the same, just the expander now uses the slightly
>> shorter arm_gen_compare_reg and the rtx costs hunk is moved under an
>> explicit case MOD.
>>
>> Note, the tests still require patch 1/3 that does this for aarch64 that I hope to
>> post a respinned version of soon.
>>
>> Ok after the prerequisite goes in?
>>
>> Thanks,
>> Kyrill
>>
>>
>> 2015-08-10  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
>>
>>       * config/arm/arm.md (*subsi3_compare0): Rename to...
>>       (subsi3_compare0): ... This.
>>       (*arm_andsi3_insn): Rename to...
>>       (arm_andsi3_insn): ... This.
>>       (modsi3): New define_expand.
>>       * config/arm/arm.c (arm_new_rtx_costs, MOD case): Handle case
>>       when operand is power of 2.
>>
>>
>> 2015-08-10  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
>>
>>       * gcc.target/aarch64/mod_2.x: New file.
>>       * gcc.target/aarch64/mod_256.x: Likewise.
>>       * gcc.target/arm/mod_2.c: New test.
>>       * gcc.target/arm/mod_256.c: Likewise.
>>       * gcc.target/aarch64/mod_2.c: Likewise.
>>       * gcc.target/aarch64/mod_256.c: Likewise.
>>
>>
>>
>> On 31/07/15 09:20, Kyrill Tkachov wrote:
>>> Ping.
>>>
>>> https://gcc.gnu.org/ml/gcc-patches/2015-07/msg02037.html
>>> Thanks,
>>> Kyrill
>>>
>>> On 24/07/15 11:55, Kyrill Tkachov wrote:
>>>> Hi all,
>>>>
>>>> This third patch implements the same algorithm as patch 1/3 but for arm.
>>>> That is, for X % N where N is a power of 2 we do:
>>>>
>>>>      rsbs    r1, r0, #0
>>>>      and     r0, r0, #(N - 1)
>>>>      and     r1, r1, #(N - 1)
>>>>      rsbpl   r0, r1, #0
>>>>
>>>> For the special case where N is 2 we do the shorter:
>>>>       cmp     r0, #0
>>>>       and     r0, r0, #1
>>>>       rsblt   r0, r0, #0
>>>>
>>>> Note that for the final conditional negate we expand to an
>>>> IF_THEN_ELSE of a NEG rather than a cond_exec rtx because the lra
>>>> dataflow analysis doesn't always deal with cond_execs correctly. The
>>>> splitters fixed in patch 2/3 then break it into a cond_exec after reload, so
>> it all works out.
>>>> Bootstrapped and tested on arm, with both ARM and Thumb2 states.
>>>>
>>>> Tests are added and shared with aarch64.
>>>>
>>>> Ok for trunk?
>>>>
>>>> Thanks,
>>>> Kyrill
>>>>
>>>> 2015-07-24  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
>>>>
>>>>         * config/arm/arm.md (*subsi3_compare0): Rename to...
>>>>         (subsi3_compare0): ... This.
>>>>         (*arm_andsi3_insn): Rename to...
>>>>         (arm_andsi3_insn): ... This.
>>>>         (modsi3): New define_expand.
>>>>         * config/arm/arm.c (arm_new_rtx_costs, MOD case): Handle case
>>>>         operand is power of 2.
>>>>
>>>>
>>>> 2015-07-24  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
>>>>
>>>>         * gcc.target/aarch64/mod_2.x: New file.
>>>>         * gcc.target/aarch64/mod_256.x: Likewise.
>>>>         * gcc.target/arm/mod_2.c: New test.
>>>>         * gcc.target/arm/mod_256.c: Likewise.
>>>>         * gcc.target/aarch64/mod_2.c: Likewise.
>>>>         * gcc.target/aarch64/mod_256.c: Likewise.
>
>